* {
    margin: 0;
    padding: 0;
}
//底部导航栏
.nav-bottom {
    display: flex;
    position: fixed;
    // align-items:center;
    // justify-content:center;
    bottom: 0;
    width: 100vw;
    height: (100 / 750)*100vw;
    box-shadow: 0 -1px 3px #888888 ;
    background-size: 100vw (114 / 750)*100vw;
    background-color: #fff;
    div {
        position: fixed;
        bottom: 0;
        width: (61 / 750)*100vw;
        height: (98 / 750)*100vw;
        background-size: cover;
        &:nth-child(1) {
            left: (61 / 750)*100vw;
            background-image: url(../image/find.png);
        }
        &:nth-child(2) {
            left: (250 / 750)*100vw;
            background-image: url(../image/bookshelf.png);
        }
        &:nth-child(3) {
            left: (439 / 750)*100vw;
            background-image: url(../image/word.png);
        }
        &:nth-child(4) {
            left: (626 / 750)*100vw;
            background-image: url(../image/my.png);
        }
    }
    
}
.fill {
    width: 100%;
    height: (100 / 750)*100vw;
}